European political integration has added a new and exciting dimension to the study of national political and administrative systems. However, comparatively little is know about the precise role of national ministries of state in either facilitating or retarding the shift towards joint rule making at the European level. Taking as an example the UK Department of the Environment's (DoE) involvement in the cumulative development of EU environmental policy since 1970, this paper examines the extent to which national environmental departments manage the process of integration or whether they are dragged along by it. It concentrates on the DoE's role in negotiating the 1987 Single European Act. It suggests that integration in the environmental sector since the Act has proceeded significantly further and faster than British negotiators originally expected, though through little conscious effort by the DoE. In fact, the DoE strongly opposed the introduction of majority voting, but was overruled by the core executive. These findings are examined against two theoretical approaches to European integration in order to reach a fuller understanding of what motivates (parts of) the British state to limit national autonomy in the process of developing European environmental rules.